1. Field of the Invention
This invention relates generally to photonic integrated circuits and, more particularly, to photonic integrated circuits which have compact architectures.
2. Description of the Related Art
Monolithic photonic integrated circuits (PICs), also sometimes referred to as planar lightwave circuits (PLCs), are increasingly deployed in modern optical telecommunication systems. These devices provide the integration of both active and passive optical components on a single substrate and are integrated with other optical components to form a multi-functional optical device for use in such systems. The gravitation to PICs is strong because it leads to the utility of providing an entire system function, let alone a component function, in a single chip in a single package. Compared to the deployment of discrete optical components, such monolithic PIC chips can significantly reduce the size of optical components necessary in the optical system, as part of a transmitter photonic integrated circuit (TxPIC) or a receiver photonic integrated circuit (RxPIC) for example, as well as significantly reduce the overall costs in a system. Examples of such TxPICs and RxPICs are disclosed in U.S. Pat. Nos. 7,283,694; 7,116,851; 7,079,715; and 7,058,246, all of which are incorporated herein in their entirety by reference.
What is needed is a photonic integrated circuit having on-chip active and passive elements located within corresponding active and passive geometric regions arranged to provide for more compact photonic integrated circuits, ultimately leading to higher chip yields and lower fabrication costs.